Form Comparison

Reduced Glutathione vs S-Acetyl Glutathione

How reduced glutathione and S-acetyl glutathione differ in potency, absorption, tolerance, and cost.

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Quick verdict. Reduced glutathione has a six-month controlled trial showing higher body stores at 1,000 mg a day. S-acetyl glutathione is marketed as better absorbed, but the evidence comes from cell studies, without published human trials. Choose reduced glutathione, or NAC if you want the cheapest well-studied route.

Side by Side

Reduced Glutathione (GSH) S-Acetyl Glutathione
Absorption Low Variable
How it is absorbed Largely broken down by gamma-glutamyl transferase in the gut. Single doses do not raise plasma glutathione, though six months at 1,000 mg daily raised body stores in one trial. Acetylating the sulfur protects it from breakdown in cell studies; the acetyl group is removed inside cells. Human pharmacokinetic data are scant.
Typical dose 250-1,000 mg daily 100-300 mg daily
Common uses antioxidant support antioxidant support
Side effects Bloating, rare cramps. None well documented.
Cost Moderate High
Also called L-glutathione, Setria SAG

When to Choose Reduced Glutathione (GSH)

Choose reduced glutathione when you want the form with the longest trial. Setria, the ingredient in the six-month trial, is a fermented reduced glutathione.

Reduced Glutathione (GSH)

The only form with a six-month controlled trial showing higher body stores, at 1,000 mg daily.

What to look for: Reduced glutathione or Setria, 500-1,000 mg daily, taken consistently.

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When to Choose S-Acetyl Glutathione

There is rarely a reason to choose S-acetyl glutathione: NAC is the cheaper, better-studied route. Marketed as the best-absorbed oral glutathione without published human trials to show it.

S-Acetyl Glutathione

There is rarely a reason to choose S-acetyl glutathione: NAC is the cheaper, better-studied route.

What to look for: S-Acetyl Glutathione named on the Supplement Facts panel, with the amount per serving stated.

Find on iHerb Affiliate link

Products on Titrate

884 of the 214,745 labels in the NIH Dietary Supplement Label Database list glutathione as an active ingredient (379 on market). 304 are sold as glutathione products by name.

Open supplement search

Glutathione does not have its own search category yet. Each product above links to its full label in the NIH database.

Related

References

Witschi A, Reddy S, Stofer B, Lauterburg BH. The systemic availability of oral glutathione. Eur J Clin Pharmacol. 1992;43(6):667-669.

Marrades RM, Roca J, Barberà JA, de Jover L, MacNee W, Rodriguez-Roisin R. Nebulized glutathione induces bronchoconstriction in patients with mild asthma. Am J Respir Crit Care Med. 1997;156(2):425-430.

Hauser RA, Lyons KE, McClain T, Carter S, Perlmutter D. Randomized, double-blind, pilot evaluation of intravenous glutathione in Parkinson's disease. Mov Disord. 2009;24(7):979-983.

Allen J, Bradley RD. Effects of oral glutathione supplementation on systemic oxidative stress biomarkers in human volunteers. J Altern Complement Med. 2011;17(9):827-833.

Sekhar RV, Patel SG, Guthikonda AP, et al. Deficient synthesis of glutathione underlies oxidative stress in aging and can be corrected by dietary cysteine and glycine supplementation. Am J Clin Nutr. 2011;94(3):847-853.

Richie JP Jr, Nichenametla S, Neidig W, et al. Randomized controlled trial of oral glutathione supplementation on body stores of glutathione. Eur J Nutr. 2015;54(2):251-263.

Sinha R, Sinha I, Calcagnotto A, et al. Oral supplementation with liposomal glutathione elevates body stores of glutathione and markers of immune function. Eur J Clin Nutr. 2018;72(1):105-111.